LBRP2 User Guide

Required materials

• 1 Laser board for the Red Pitaya
• 1 Red Pitaya board
• 1 ethernet cable
• 1 power supply
• 2 SMA cables
• 1 SD card with Ubuntu for LBRP image installed

Quickstart

1. Mount your Laser board on the Red Pitaya and connect the SMA cables.
2. Insert your SD card in the Red Pitaya.
3. Connect your Red Pitaya to either a router or a computer with an ethernet cable.
4. Plug in the power supply connected to the PWR slot of the Red Pitaya.

Web interface

Open your internet browser and enter your Red Pitaya IP address in the url bar.

Python API

You can control the laser board programmatically with the Python API. You can find examples of Python scripts on GitHub.

Interface with the Red Pitaya

Koheron LBRP2 uses the Red Pitaya extension connectors E1 and E2 for power supply, slow monitoring and control. Modulation input is connected to the 125 MSps DAC via the SMA front connector. Detection output is connected to the 125 MSps ADCs via the SMA front connector.

Digital interface

E1 connector

Pin	Description	Connected to
4	DIO0_N	EEPROM (DO)
5	DIO1_P	EEPROM (DI)
6	DIO1_N	EEPROM (SK)
7	DIO2_P	EEPROM (CS)
17	DIO7_P	Laser enable
18	DIO7_N	Reset overvoltage

Analog interface

E2 connector

Pin	Description	Connected to
13	Analog Input 0	Laser current monitor
15	Analog Input 2	Laser power monitor
20	Analog Output 3	Laser current bias

Note: The laser current bias is related to the analog output voltage V_AO by I_LD (mA) = 47.6 * V_AO (V).